His first discovery was the asteroid 267 Tirza in 1887. He photographed 433 Eros on the very night of its discovery by Gustav Witt, but was not able to act quickly enough before Witt announced his find.

Although he started searching for asteroids in the era of visual detection, by 1891 Max Wolf had pioneered the use of astrophotography to drastically speed up the rate of detection of asteroids, and both Wolf and Charlois separately discovered far more asteroids than would have been feasible by visual detection.

At the age of 46, he was murdered by his brother-in-law (the brother of his first wife), who held a grudge against him because he had remarried. The man was found guilty and given a life sentence of hard labor in New Caledonia.